diff --git a/mkspecs/linux-g++-32/qmake.conf b/mkspecs/linux-g++-32/qmake.conf
index 9241991f..cc18f1b1 100644
--- a/mkspecs/linux-g++-32/qmake.conf
+++ b/mkspecs/linux-g++-32/qmake.conf
@@ -1,6 +1,6 @@
 #
 #
-# qmake configuration for linux-g++
+# qmake configuration for linux-g++-32
 #
 
 MAKEFILE_GENERATOR	= UNIX
@@ -16,7 +16,7 @@ QMAKE_YACCFLAGS		= -d
 QMAKE_YACCFLAGS_MANGLE  = -p $base -b $base
 QMAKE_YACC_HEADER       = $base.tab.h
 QMAKE_YACC_SOURCE       = $base.tab.c
-QMAKE_CFLAGS		= -m32 -pipe
+QMAKE_CFLAGS		= -m32 -pipe -fvisibility=hidden
 QMAKE_CFLAGS_DEPS	= -M
 QMAKE_CFLAGS_WARN_ON	= -Wall -W
 QMAKE_CFLAGS_WARN_OFF	= -w
@@ -27,7 +27,7 @@ QMAKE_CFLAGS_YACC	= -Wno-unused -Wno-parentheses
 QMAKE_CFLAGS_THREAD	= -D_REENTRANT
 
 QMAKE_CXX		= g++
-QMAKE_CXXFLAGS		= $$QMAKE_CFLAGS
+QMAKE_CXXFLAGS		= $$QMAKE_CFLAGS -fvisibility-inlines-hidden
 QMAKE_CXXFLAGS_DEPS	= $$QMAKE_CFLAGS_DEPS
 QMAKE_CXXFLAGS_WARN_ON	= $$QMAKE_CFLAGS_WARN_ON
 QMAKE_CXXFLAGS_WARN_OFF	= $$QMAKE_CFLAGS_WARN_OFF
diff --git a/mkspecs/linux-g++-64/qmake.conf b/mkspecs/linux-g++-64/qmake.conf
index 4f982d2f..05015e54 100644
--- a/mkspecs/linux-g++-64/qmake.conf
+++ b/mkspecs/linux-g++-64/qmake.conf
@@ -1,6 +1,6 @@
 #
 #
-# qmake configuration for linux-g++
+# qmake configuration for linux-g++-64
 #
 # mkspec for platforms that have both lib and lib64
 # directories, like the AMD Opteron.
@@ -19,7 +19,7 @@ QMAKE_YACCFLAGS		= -d
 QMAKE_YACCFLAGS_MANGLE  = -p $base -b $base
 QMAKE_YACC_HEADER       = $base.tab.h
 QMAKE_YACC_SOURCE       = $base.tab.c
-QMAKE_CFLAGS		= -pipe
+QMAKE_CFLAGS		= -pipe -fvisibility=hidden
 QMAKE_CFLAGS_DEPS	= -M
 QMAKE_CFLAGS_WARN_ON	= -Wall -W
 QMAKE_CFLAGS_WARN_OFF	= -w
@@ -30,7 +30,7 @@ QMAKE_CFLAGS_YACC	= -Wno-unused -Wno-parentheses
 QMAKE_CFLAGS_THREAD	= -D_REENTRANT
 
 QMAKE_CXX		= g++
-QMAKE_CXXFLAGS		= $$QMAKE_CFLAGS
+QMAKE_CXXFLAGS		= $$QMAKE_CFLAGS -fvisibility-inlines-hidden
 QMAKE_CXXFLAGS_DEPS	= $$QMAKE_CFLAGS_DEPS
 QMAKE_CXXFLAGS_WARN_ON	= $$QMAKE_CFLAGS_WARN_ON
 QMAKE_CXXFLAGS_WARN_OFF	= $$QMAKE_CFLAGS_WARN_OFF